While every developer has kind of accepted their existence, they are suddenly there when we'd desperately need them to not show up. How often did you writeif($obj === null) in your PHP code? Can't there be a better, more elegant and fault-tolerant solution to the problem?
His solution is to create a PHP version of this "Optional" functionality (via an abstract class) that allows some evaluation of the returned value from method calls on the object. Methods like "isPresent", "getOrElse", "of" and "fromNullable" make it easier to work with null values instead of just the triple-equals checking. He includes not only the code for the classes you'll need to implement it but examples of it in use - an "Optional" abstract class and two child classes, "Present" and "Absent".